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Clostridium difficile infection rates have been rising within the last decade and more pediatric patients have been suffering from this type of infection. However, this bacterium is a well-known contaminant in the normal flora of the colon in patients under the age of 2 years, and therefore consensus guidelines have recommended against routine testing for this infection, unless clinically indicated. We present here a case of a very young infant who presented with symptoms of food refusal, poor weight gain, abdominal distention, and colitis noted on imaging. Endoscopic evaluation demonstrated the presence of pseudomembranous colitis, so the patient was treated with antibiotics against C. difficile and recovered fully. This case demonstrates the importance of keeping C. difficile colitis in your differential diagnosis, even at a very young age.

Serine/threonine kinase 11 (STK11) is known as a critical tumor-suppressor gene that is frequently mutated in a broad spectrum of human cancers. Among these, the p.F354L mutation of STK11 has been identified in sporadic colon or lung cancer cases. Here, we report the case of a 75-year-old male patient who underwent surgical treatment for multiple tumors of the gastrointestinal system. Genetic mutations were screened in all resected samples, including duodenal high-grade adenoma, gastric high-grade adenoma, rectal adenocarcinoma, and liver metastasis of rectal adenocarcinoma, by next-generation sequencing for mutational hotspots involving 50 oncogenes and tumor suppressor genes. The characteristic hamartomatous polyp of Peutz-Jeghers syndrome was not detected in any tumor specimen. However, all samples as well as the normal rectal mucosa harbored the genetic mutation p.F354L in STK11. In addition, somatic mutations coexisted in the tumor samples, including KRAS p.A146T, TP53 p.G238X, and APC p.T1556fs in the duodenal adenoma; TP53 p.G238Y and APC p.T1556fs in the gastric adenoma; and TP53 p.R282W in the rectal adenocarcinoma and metastatic liver cancer. No somatic mutation was detected in the normal rectal mucosa as a control sample. To our knowledge, this is the first report of an STK11 germline mutation in a patient with multiple tumors of the gastrointestinal tract.

Intestinal parasitic infections are a major public health issue across the world and particularly in rural and urban areas of tropical and subtropical countries. Those at increased risk include inhabitants of poor and disadvantaged regions, which are more likely to have inadequate environmental sanitation, insufficient water supply, greater contact rates with reservoirs of infection, limited health literacy, and socioeconomic disparities. Of the intestinal nematodes (roundworms) that parasitize the human gastrointestinal tract, Ascaris lumbricoides is the largest in terms of size. It causes ascariasis, a "neglected tropical disease," or NTD, that is among the most common helminthic human infections worldwide with an estimated 800 million to 1.2 billion people infected. It causes more than 60,000 deaths annually. However, in more than 85% of cases, infections do not result in symptoms - especially in individuals infected with a small number of worms. Thus, many individuals with intestinal ascariasis remain undiagnosed for years until either they experience symptoms and seek medical attention, the macroscopic adult worms are passed with the stool, or the adult worms are incidentally discovered during routine endoscopic procedures. Here, we present an interesting case of an elderly Bangladeshi man with seemingly innocuous complaints of intermittent mild abdominal symptoms and no recent travel history, who was discovered to have intestinal ascariasis during a screening colonoscopy.

A 68-year-old Japanese man presented with Ascaris lumbricoides discharge from his mouth. The infection was suspected to have occurred while the patient was in the Philippines. This A. lumbricoides migration occurred because a proton pump inhibitor was used and Billroth I resection had been performed, which reduced gastric acid secretion and increased gastric pH. In addition, the pylorus had been removed during Billroth I resection, enabling easy access to the stomach. The number of imported foods, of infected migrants and refugees, and of overseas travels is increasing, and these factors may lead to an increase in A. lumbricoides infection even in countries with a typically low incidence of such infections. Clinicians should bear in mind that parasitic infections may occur in nonendemic areas.

Clostridium septicum is a highly virulent pathogen which is associated with colorectal malignancy, hematological malignancy, immunosuppression, diabetes mellitus and cyclical neutropenia. Presentation may include disseminated clostridial infection in the form of septicemia, gas gangrene, and mycotic aortic aneurysms. We report the case of a 62-year-old female presenting with necrotizing fasciitis of her left thigh and subsequently developing rectal bleeding. While she was being treated with empiric antibiotics, her blood culture was found to be positive for C. septicum. We would like to highlight the importance of early colorectal cancer screening in minimizing the occurrence of undetected tumors which provide an optimal growth environment for C. septicum, leading to localized and/or remote infection.